1. Field of the Invention
The present invention concerns a device for measuring the magnitude of a force applied to the free end of a cantilever beam. In particular, the present invention concerns the incorporation of a cantilevered beam in a weighing scale and measuring the strain in the beam when the same is subjected to the weight of an object being weighed. The measured strain is then converted to a digital read out.
2. Prior Art
U.S. Pat. No. 3,863,724 describes such a measuring circuit, which uses the signal originating from the sensor of a strain-gauge to yield a numerical result equivalent to the strain undergone. In particular, the device utilizes a conventional analog-to-digital converter.
When implementing an electronic circuit of this high-quality type, a major complication appears in the analog amplifying circuits. This is particularly true, if one must maintain great precision in terms of ambient-temperature variations, or of supply-voltage variations (if the equipment must be supplied from a battery), as well as in terms of stability in time. Indeed, this requires the insertion of voltage-stabilizing circuits and of drift-compensating circuits, and the making of many adjustments at the end of the manufacture. All these factors have an unfavorable effect on the cost of these electronics.